Metal halide catalyst, method of producing the catalyst, polymerization process employing the catalyst, and polymer produced by the polymerization process

ABSTRACT

A polymerization catalyst system is formed by producing a solution of a halide of scandium, yttrium, or a rare earth metal and an alcohol; contacting the solution with a halide ion exchanging source to form a solid. The catalyst thus produced can be combined with an organometallic cocatalyst. Polymers with multimodal molecular weight distribution are produced when a diol is used to prepare the catalyst and an organoaluminum halide is used as cocatalyst. Polymers with broad molecular weight distribution of the unimodal type are produced when using a trialkylaluminum compound or an alkyl aluminum hydride.

BACKGROUND

The present invention relates to metal halide catalysts.

In the polymerization of alpha-olefins, it is known to use catalystsystems comprising a transition metal compound and an organometalliccompound. It is further known that the productivity of such catalystsystems can generally be improved if the transition metal compound isemployed in conjunction with a metal halide, such as MgCl₂. Thecatalysts described above produce polymers of narrow molecular weightdistribution (MWD) and do not exhibit a multimodal or broad molecularweight distribution.

For many applications, such as extrusion and molding processes, it ishighly desirable to have polymers which have a broad molecular weightdistribution of the unimodal and/or the multimodal type. Such polymersevidence excellent processability, i.e. , they can be processed at afaster throughput rate with lower energy requirements with reduced meltflow perturbations.

It is also highly desirable to produce multimodal or broad molecularweight distribution polymers directly in a single reactor, withouthaving to blend polymers having different molecular weights anddistribution in order to obtain the advantages of this invention.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a catalyst system usefulfor the polymerization of olefins of broad molecular weightdistribution.

It is another object of this invention to provide a method to prepare animproved catalyst system useful for the polymerization of olefins.

It is another object of this invention to provide a method for thepolymerization of olefins with a multimodal molecular weightdistribution in a single reactor.

It is another object of this invention to provide a method for thepolymerization of olefins with improved processability.

In accordance with the invention, a catalyst is produced by admixing ametal halide selected from the group consisting of halides of scandium,yttrium, and rare earth metal halides as herein described and an alcoholto form a solution; the thus formed solution is then combined with ahalide ion exchanging source.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are a graphic representation of the results obtained in theexamples. FIG. 1 represents the results in Table 4. FIG. 2 representsthe results in Table 6.

DETAILED DESCRIPTION OF THE INVENTION Catalyst

The present invention is concerned with new, high productivity catalystswhich employ scandium, yttrium, or rare earth metal halides which arecontacted with an alcohol to form a solution; a solid precipitate isformed when the solution is combined with a halide ion exchangingsource, and finally an organometal cocatalyst can be used with thecatalyst.

The metal halides are employed in the +3 oxidation state insubstantially anhydrous form and comprise scandium and yttrium and rareearth elements starting with lanthanum (atomic number 57) and endingwith lutetium (atomic number 71) of the Mendeleev Periodic Table. Asused herein by the term "Mendeleev Periodic Table" is meant the PeriodicTable of the Elements as shown in the inside front cover of Perry,Chemical Engineer's Handbook, 4th Edition, McGraw Hill & Co. (1963).Generally, the lanthanide chlorides are preferred because ofavailability. Examples of preferred compounds include neodymiumtrichloride, praseodymium trichloride, lanthanum trichloride, yttriumtrichloride and mixtures thereof. Neodymium trichloride is particularlypreferred because of its efficacy.

Alcohols that can be used include either monohydroxy or polyhydroxyalcohols. Aliphatic or aromatic alcohols can be employed. The aliphaticalcohols can be saturated or unsaturated. Suitable monohydroxy alcoholsare those containing 1 to 20 carbon atoms, preferably from 2 to 16carbon atoms. Examples of suitable monohydroxy alcohols includemethanol, ethanol, isopropanol, hexanol, 2-ethyl hexanol, octanol,decanol, dodecanol, and hexadecanol.

Suitable polyhydroxy alcohols include diols and glycerols. Suitablediols are diols containing 2 to 20 carbon atoms, preferably 1,2 diolscontaining from 2 to 16 carbon atoms. Examples of suitable diols include1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-hexanediol,1,2-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-hexadecanedioland 1,20-eicosanediol. Diols are especially preferred for producingpolymers having multimodal molecular weight distribution.

The alcohol is present in an amount sufficient to form a solution withthe metal halide. The amount required to form a solution will varydepending on the alcohol used and the metal halide present.

The moles of alcohol per mole of metal halide to be employed accordingto the invention is generally in the broad range of about 1 to about 30,preferably in the range of about 2 to about 20, and most preferably inthe range of 3 to 15. Examples of amounts of especially preferredalcohols include moles of alcohol per mole of metal halide of greaterthan 4 when the alcohol is 1,2-hexadecanediol; greater than 5 for1,2-octanediol; and greater than 10 for 1-octanol.

The metal halide and the alcohol can be combined with a suitable drysolvent or diluent (i.e. one essentially free of water). Typicalsolvents or diluents include, for example, normally liquid hydrocarbonshaving 3 to 12 carbon atoms such as n-heptane, methylcyclohexane,toluene, xylenes, and mixtures thereof. Toluene is the preferredsolvent.

Generally, the amount of solvent or diluent employed can vary over abroad range. Usually the amount of solvent or diluent per gram of metalhalide is within the range of about 5 to 300 grams, preferably in therange of about 10 to about 200 grams and most preferably from 10 to 100grams.

The temperatures employed in the combination of the metal halide, thealcohol, and solvent can vary over a wide range, generally being in therange of about 0° C. to about 200° C., preferably from about 15° C. to100° C., and most preferably from 20° C. to 75° C. The pressure employedcan vary over a wide range, generally being in the range of about 0 toabout 200 psig, preferably in the range of about 0 to about 100 psig,and most preferably in the range of 0 to 50 psig. Conditions areselected so that the reaction product will be in solution. The time ofreaction can vary broadly from about 1 minute to about 72 hours,preferably from about 5 minutes to about 24 hours, and most preferablyfrom 5 minutes to 10 hours.

The metal halide and alcohol solution is then reacted with a halide ionexchanging source to produce a solid catalyst. The halide ion exchangingsource is selected from the halide containing compounds of elements ofGroups IVA and VA of the Mendeleev Periodic Table. Further according tothe invention, the Group IVA and VA halide containing compounds can becombined with transition metal halides of Groups IVB and VB and organicacid halides. The term halide ion exchanging source is used herein todenote those compounds capable of adding halogen to the solution andpromoting the catalytic activity for olefin polymerization.

Currently preferred halide ion exchanging sources include halides ofGroup IVA and VA transition metals, such as titanium tetrachloride,vanadium oxychloride, zirconium oxychloride, and zirconiumtetrachloride, and combinations of Group IVA and VA halides with thehalides of Group IVB and VB elements, such as COCl₂, PCl₃, SiCl₄, SnCl₄,CCl₄ and acid chlorides of the formula R'COCl where R' is an aliphaticor aromatic radical preferably containing 1 to 20 carbon atoms.Particularly preferred halide ion exchanging sources include titaniumtetrahalides, e.g. titanium tetrachloride; and combinations of titaniumtetrahalides and halogenated silicon compounds, e.g. silicontetrachloride and trichlorosilane.

The metal halide solution can be contacted with the halide ionexchanging source neat or in a liquid medium. Generally, the metalhalide solution is contacted in a liquid diluent containing the halideion exchanging source. Examples of suitable diluents include n-pentane,n-heptane, cyclohexane, benzene, toluene, and m-xylene.

The temperature employed in contacting the metal halide solution and thehalide ion exchanging source is generally in the range of about -25° C.to about 250° C., preferably about 0° C. to about 200° C., and mostpreferably from 0° C. to 100° C. The pressure employed can vary over awide range, generally being in the range of about 0 to about 200 psig,preferably in the range of about 0 to about 100 psig, and mostpreferably in the range of 0 to 50 psig. The time of reaction can varybroadly from about 1 minute to about 72 hours, preferably from about 5minutes to 24 hours, and most preferably from 5 minutes to 10 hours.

While the moles of halide ion exchanging source per mole of metal halidecan be selected over a wide range, generally the range will be fromabout 0.1 to about 1000, preferably from about 0.5 to about 500, andmost preferably from 1 to 100. Following the treatment of the metalhalide solution with the halide ion exchanging source to form a solidcatalyst, the surplus halide ion exchanging source can be removed bywashing with a dry liquid of the type used in the previous step. Theresulting product can be stored under dry nitrogen until use.

Cocatalyst

In the polymerization of olefins, the inventive catalyst system can beused with a suitable cocatalyst of the type generally used withtitanium-containing olefin polymerization catalysts. Typical examplesinclude organometallic compounds of Groups I, II, and III of theMendeleev Periodic Table, i.e. alkali metal alkyls or aryls,dialkylmagnesium, dialkylzinc, Grignard reagents, and organoaluminumcompounds.

For producing a polymer exhibiting multimodal molecular weightdistribution, the preferred organometallic compounds are theorganoaluminum halides of the general formula

    R.sub.n AlX.sub.3-n

wherein R is a hydrocarbyl radical containing 1 to 20 carbon atoms, X isa halogen, preferably chlorine or bromine, and n is 1 to 2. Thussuitable types of organoaluminum halides are selected fromdihydrocarbylaluminum halides and hydrocarbylaluminum dihalides, andmixtures thereof.

Examples include dimethylaluminum bromide, diethylaluminum chloride(DEAC), diisobutylaluminum bromide, didodecylaluminum chloride,dieicosylaluminum bromide, ethylaluminum dichloride (EADC),ethylaluminum sesquichloride (EASC), and mixtures thereof.Diethylaluminum chloride is especially preferred. Preferably theorganometallic compound has been dissolved in a hydrocarbon solvent.Diethylaluminum chloride is most preferred.

For producing a polymer exhibiting broad molecular weight distributionof the unimodal type, the preferred organometallic compounds are theorganoaluminum compounds of the general formula

    R.sub.n AlX.sub.3-n

wherein R is a hydrocarbyl radical containing 1 to 20 carbon atoms, X isa halogen or hydrogen, and n is 1-3. Examples of suitable organoaluminumcompounds are trimethylaluminum, triethylaluminum, diethylaluminumhydride, triisopropenylaluminum, tricyclobexylaluminum,triisobutylaluminum, disobutylaluminum hydride, tridodecylaluminum,trieicosylaluminum, tribenzylaluminum, and mixtures thereof. For thepolymerization of monomers consisting predominantly of ethylene, it iscurrently preferred to use a trialkylaluminum cocatalyst such astriethylaluminum (TEA).

The amount of cocatalyst employed in the catalyst system during thepolymerization process can vary widely. Generally, the moles oforganometal cocatalyst per mole of halide ion exchanging source in theinventive catalyst system is about 0.1 to about 1000, preferably fromabout 1 to about 750, and most preferably from 5 to 700.

If desired, the catalyst system can be mixed with a particulate diluentsuch as silica, silica-alumina, silica-titania, magnesium dichloride,magnesium oxide, polyethylene, polypropylene, and poly(phenylenesulfide), prior to using the composition in a polymerization process.The weight ratio of diluent to catalyst can range from about 0.01 toabout 1000.

Reactants

The inventive catalyst system is useful for the polymerization ofolefins. Typical polymerizable olefins include the aliphatic monoolefinshaving 2 to 18 carbon atoms. The term polymerization is used herein toinclude both homo- and copolymerization. In copolymerization otherpolymerizable monomers can be employed with the olefins, such asconjugated and nonconjugated dienes.

Suitable olefins include ethylene, propylene, 1-butene, 1-hexene,4-methyl-l-pentene, styrene, 1,3-butadiene, isoprene, 1,5-hexadiene,trans-1,3-pentadiene, trans-1,3-hexadiene,trans-2-methyl-1,3-pentadiene, trans-3-methyl-1,3-pentadiene,2,3-dimethyl-1,3-butadiene, trans-trans-2,4-hexadiene and mixturescontaining 2 or more polymerizable unsaturated hydrocarbons. Aparticular group of olefins to be polymerized according to the inventionincludes unsaturated hydrocarbons having 2 to 6 carbon atoms and havingat least one polymerizable ethylenic double bond. The inventive catalystis particularly well suited for the preparation of ethylene homopolymersand copolymers which contain at least 90 mole percent, and preferably atleast 95 mole percent ethylene. In one especially preferred embodiment99 to 99.6 mole per cent ethylene is used and 0.4 to 1 mole per cent ofa 4 to 10 carbon atom comonomer is used; in this embodiment bexene is aparticularly desirable comonomer because of cost, availability andefficacy.

The polymerization reaction can be carried out in the presence of asolvent or a diluent. Suitable as the solvent for the instant reactionsystem are inert hydrocarbons such as n-butane, isobutane, n-pentane,n-bexane, n-heptane, isooctane, cyclohexane, methylcyclohexane, benzene,toluene, xylene, tetralin, decalin, and other aliphatic, alicyclic,aromatic hydrocarbons, or mixtures thereof. The polymerization can becarried out in gas phase in the absence of solvent or diluent.

Polymerization Conditions

The catalyst system of this invention, that is the catalyst andcocatalyst, can be employed in a batchwise, semi-continuous, or in acontinuous polymerization process. Generally, the present polymerizationreaction can be carried out at a temperature in the range of about 0° C.to about 200° C., preferably a temperature of about 25° C. to about 150°C., and most preferably from 25° C. to 100° C. Polymerization pressurecan vary depending on the type of monomer, the catalyst activity, thedesired degree of polymerization, etc. Generally polymerization pressurecan be subatmospheric or superatmospheric pressure up to about 300atmospheres, preferably from atmospheric pressure to about 100atmospheres, and most preferably from atmospheric pressure to 50atmospheres. Generally contacting time for the catalyst and the olefinscan vary broadly from about 1 minute to about one week, more preferablyfrom about 5 minutes to about 24 hours, and most preferably from 5minutes to 5 hours.

Generally, when using a solvent or diluent in the instant polymerizationreaction, it is convenient to introduce olefin into a dispersioncontaining the catalyst system of the present invention in the solventor diluent. The catalyst composition can be added in its whole amount tothe polymerization system at the start or it can be added portion-wiseover the period for the polymerization.

In a batch process of polymerizing ethylene, for example, a stirredautoclave is conditioned by purging with dry nitrogen and then with thehydrocarbon diluent that is to be employed in the polymerization processsuch as isobutane, for example. Generally, although order is immaterial,the cocatalyst is charged through an entry port followed by thecatalyst. After closing the port, hydrogen, if used, can be added, andthe hydrocarbon diluent can then be charged.

The reactor can then be heated to the desired reaction temperature, e.g.about 50° to about 120° C., the ethylene is admitted and maintained at apartial pressure within a range of about 0.5 to about 5.0 MPa (70-725psig). At the end of the reaction period, generally about 1 hour forbench scale testing, the polymerization reaction is terminated byventing unreacted olefin and diluent. The reactor is then opened and thefree-flowing white ethylene polymer can be collected and dried.

In a continuous process, for example, a suitable reactor such as a loopreactor is continuously charged with suitable quantities of solvent ordiluent, catalyst, cocatalyst, olefin, and hydrogen, if used. Thecontact between the catalyst system and monomer can be effected byvarious ways. For example, the olefin can be contacted with the catalystin the form of a fixed bed, a slurry, a fluid bed, or a movable bed.

The polymerization reaction can be carried out in the presence ofmolecular hydrogen to regulate the molecular weight of the olefinpolymers, as known in the art.

Products

The reactor product is continuously or intermittently withdrawn, and thepolymer recovered, e.g. flashing diluent and unreacted olefin and dryingthe product. In order to recover a produced polymer from thepolymerization system, the crude polymerization product is for exampletaken up and subjected to flash separation, solvent extraction, hotfiltration under a pressure, or centrifugal separation to yield asubstantially pure polymeric product. A selection of the polymerizationconditions for the process of the present invention, as well as themethod for the recovery and purification of the polymeric product willbe understood by those skilled in the art from the conventional low ormodest pressure polymerization processes for olefins.

The following examples will serve to show the present invention indetail by way of illustration and not by way of limitation.

EXAMPLES

A further understanding of the present invention and its various aspectsand advantages will be provided by the following examples. The catalystsystems used in the following examples, unless indicated otherwise, wereprepared by charging a solution prepared by combining 1 mole NdCl₃ and 5moles 1,2-octanediol per mole Ti, and toluene to a reactor. TiCl₄ wasadded to the solution, the temperature was raised to 80° C., and thereaction continued for 1 hour. The resulting solid catalyst wasrecovered, washed, and dried.

In the following examples, unless indicated otherwise, thepolymerization reactions were performed in a one liter, stirredautoclave. Prior to the reactions, the autoclave was washed thoroughlywith dry cyclohexane and purged with nitrogen. The catalyst wassuspended in cyclohexane and charged through a small port under acounter flow of ethylene. The reactor was sealed. Isobutane (500 ml) wasadded to the reactor and the desired temperature obtained andmaintained. Ethylene pressure was increased to a total reactor pressureof 550 psig. At the end of the reaction, solvent and ethylene wererapidly vented and the solid polymer was collected and dried.

The catalyst used in Examples I-V was prepared by combining 1.005 gNdCl₃, 2.931 g 1,2-octanediol and 20 mL toluene in a reaction vessel atambient temperature to form a solution. The rapid addition of 5.0 mLTiCl₄ produced an orange-yellow slurry. The reaction mixture was heatedat 75° C. for 1 hour then 30 mL chclohexane was added. A yellow slurrywas produced. The solid catalyst was washed with cyclohexane then usedas a cyclohexane slurry. The concentration of the slurry was determinedto be 47 mg catalyst/ml and the catalyst contained 13% Ti by weight.

Polymerizations in Examples I-V, unless otherwise indicated, were runusing 7.1 mg catalyst, a temperature of 90° C. for 37.5 minutes, with apartial pressure of hydrogen of 40 psig, a 25 g hexane charge, and 320moles of diethylaluminum chloride (DEAC) per mole of Ti. Polymers ofbimodal molecular weight distribution were produced.

The catalyst used in Examples VI-X was prepared by combining 1.010 gNdCl₃, 2.940 g 1,2-octanediol and 20 mL toluene in a reaction vessel atambient temperature to form a solution. The slow addition of 5.0 mLTiCl₄ over a period of about 30 minutes produced an orange-yellowslurry. The reaction mixture was heated at 80°-85° C. for 1.5 hours.Then 30 mL cyclohexane was added. A yellow slurry was produced. Thesolid catalyst was washed with cyclohexane and then used as acyclohexane slurry. The concentration of the slurry was determined to be27 mg catalyst/ml and the catalyst contained 8% Ti by weight.

Polymerizations in Examples VI-X, unless otherwise indicated, were runusing 5.0 mg catalyst, a temperature of 90° C. for 37.5 minutes, withhydrogen at a partial pressure of 40 psig, a 25 g hexane charge, and 260moles of triethylaluminum (TEA) per mole of Ti. Polymers of narrow tobroad molecular weight distribution of the unimodal type were produced.Terms used in the tables are defined as follows:

Activity is expressed as grams of polymer per gram of catalyst per hour.

MI is melt index, g/10 minutes, ASTM D1238-65T, conditions E.

HLMI is high load melt index, g/10 minutes, ASTM D1238-65T, condition F.

SR is shear response and is the ratio of HLMI/MI.

Density is g/mL.

HI is heterogeneity index and is the ratio of M_(w) /M_(n).

M_(w) is the weight average molecular weight.

M_(n) is the number average molecular weight.

Mp(low) is peak molecular weight of low fraction.

WF.sub.(low) is the percent weight fraction of the low molecularfraction.

Mp(high) is peak molecular weight of high fraction.

DEAC/Ti is the ratio of moles of diethylaluminum chloride per mole ofTi.

H₂ is the partial pressure of hydrogen, ΔP(H₂), as psig, measured as thepressure drop from a 1 liter vessel.

Hexene is grams of 1-hexene comonomer charged to the reactor.

TEA/Ti is the ratio of moles of triethylaluminum per mole of Ti.

EXAMPLE I

In Example I, a series of polymerization runs was carried out usingvaryious ratios of diethylaluminum chloride (DEAC) to Ti. The resultsare summarized in Table 1.

Table I demonstrates that useful catalyst systems are produced byreacting a metal halide, an alcohol, and a transition metal compound inconjunction with an organoaluminum halide cocatalyst. Good catalystactivity for producing polymer with bimodal molecular weightdistribution is indicated by the high HI values. As the amount of DEACis increased, the density, heterogeneity index and the weight fractionof the low molecular weight fraction increase.

EXAMPLE II

Another series of polymerization runs was carried out varying thepartial pressure of hydrogen. The results are summarized in Table 2.

Table 2 demonstrates a typical response to increasing amounts ofhydrogen, i.e. the melt index and density increase and the molecularweight decreases. Activity of the catalyst appears to decrease somewhat.

EXAMPLE III

Another series of polymerization runs was carried out varying the amountof hexane used as comonomer. The results are summarized in Table 3.

Hexene is incorporated, as indicated by the decreasing density andmolecular weight. The peak molecular weight of the low fractionincreases and the weight fraction of the low molecular weight fractionincreases with increasing hexene.

EXAMPLE IV

Another series of polymerization runs was carried out varying the lengthof time used in the polymerization reaction. The time in Table 4 isrepresented in minutes. The results are summarized in Table 4 and FIG.1.

Table 4 demonstrates the unusual result of increasing molecular weightof the low molecular weight fraction with increasing time. The HIdecreases as the molecular weight peaks grow closer together. FIG. 1also clearly demonstrates the bimodal character of the polymer.

EXAMPLE V

A series of polymerization reactions was run varying the temperature ofthe polymerization reaction. The results are summarized in Table 5. Thetotal pressure in these runs remains constant, so that as thetemperature increases, the amount of ethylene decreases.

Table 5 demonstrates that catalyst activity decreases and weightfraction of the low molecular weight fraction increases with increasingtemperature. At 100° C. the activity is decreased considerably.

                                      TABLE I                                     __________________________________________________________________________    DEAC/Ti                                                                             Activity                                                                           MI SR Density                                                                            HI Log MW                                                                             M.sub.p (low)                                                                      WF (low)                                                                            M.sub.p (high)                       __________________________________________________________________________    110   4821 0.71                                                                             25.3                                                                             0.9482                                                                             12.40                                                                            5.0787                                                                             1844 10.23 60646                                320   8079 1.04                                                                             26.4                                                                             0.9524                                                                             22.23                                                                            5.0785                                                                             1322 17.78 58573                                530   6883 1.78                                                                             26.5                                                                             0.9536                                                                             30.50                                                                            5.0049                                                                             1057 26.29 59350                                __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________    H.sub.2 psig                                                                      Activity                                                                           MI SR Density                                                                            HI log MW                                                                             M.sub.p (low)                                                                      WF (low)                                                                            M.sub.p (high)                         __________________________________________________________________________    10  8860 0.10                                                                             28.0                                                                             0.9478                                                                             30.60                                                                            5.3160                                                                             1520 16.60 78830                                  40  8079 1.04                                                                             26.4                                                                             0.9524                                                                             22.23                                                                            5.0785                                                                             1322 17.78 58573                                  70  6641 5.54                                                                             30.0                                                                             0.9551                                                                             17.00                                                                            4.8831                                                                             1095 17.77 39130                                  __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________    Hexene                                                                            Activity                                                                           MI SR Density                                                                            HI log MW                                                                             M.sub.p (low)                                                                      WF (low)                                                                            M.sub.p (high)                         __________________________________________________________________________     0  8185 0.39                                                                             27.7                                                                             0.9588                                                                             23.43                                                                            5.2380                                                                             1111 10.47 62913                                  25  8079 1.04                                                                             26.4                                                                             0.9524                                                                             22.23                                                                            5.0785                                                                             1322 17.78 58573                                  50  6375 2.09                                                                             27.0                                                                             0.9502                                                                             21.40                                                                            4.9533                                                                             1504 25.17 54330                                  __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    Time                                                                             Activity                                                                           MI SR Density                                                                            HI log MW                                                                             M.sub.p (low)                                                                      WF (low)                                                                            M.sub.p (high)                          __________________________________________________________________________    15.0                                                                             10496                                                                              0.71                                                                             24.0                                                                             0.9483                                                                             30.60                                                                            5.1072                                                                             1020 19.06 57920                                   37.5                                                                             8079 1.04                                                                             26.4                                                                             0.9524                                                                             22.23                                                                            5.0785                                                                             1322 17.78 58573                                   60.0                                                                             6595 1.08                                                                             28.5                                                                             0.9534                                                                             19.05                                                                            5.0728                                                                             1545 17.45 60530                                   __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    Temp                                                                              Activity                                                                           MI SR Density                                                                            HI log MW                                                                             M.sub.p (low)                                                                      WF (low)                                                                            M.sub.p (high)                         __________________________________________________________________________     80° C.                                                                    8968 0.31                                                                             27.0                                                                             0.9506                                                                             24.30                                                                            5.2429                                                                             1337 12.72 70310                                   90° C.                                                                    8079 1.04                                                                             26.4                                                                             0.9524                                                                             22.23                                                                            5.0785                                                                             1322 17.78 58573                                  100° C.                                                                    2972 15.30                                                                            -- 0.9500                                                                             18.50                                                                            4.6613                                                                             1236 43.21 42100                                  __________________________________________________________________________

EXAMPLE VI

Examples VI-X were conducted using TEA as cocatalyst. The polymersproduced with TEA as cocatalyst exhibited narrow to broad molecularweight distribution.

Polymerizations in Examples VI-X, unless otherwise indicated, were runusing a temperature of 90° C. for 37.5 minutes, with hydrogen at apartial pressure of 40 psig, a partial pressure of hexane of 25 psig,and 260 moles TEA per mole of Ti.

Example VI shows a series of polymerizations using varying amounts ofTEA. The results are represented in Table 6 and FIG. 2.

                  TABLE 6                                                         ______________________________________                                        TEA/Ti Activity  MI     SR   Density                                                                              HI    log MW                              ______________________________________                                         30    17414     0.93   23   0.9455 3.85  5.0755                              260    10313     0.87   32   0.9537 8.40  5.1105                              480     5085     1.63   45   0.9609 14.51 5.0453                              ______________________________________                                    

Table 6 demonstrates that useful catalyst systems are produced byreacting a metal halide, a diol, and a transition metal compound inconjunction with an organoaluminum cocatalyst. Good catalyst activityfor producing polymer with broad molecular weight distribution isindicated by the increasing HI values. Table 6 shows decreasing activitywith increasing TEA. Density increases with increasing TEA. In generalthe HI using TEA is lower than the HI for DEAC.

EXAMPLE VII

In Example VII a series of polymerization runs was carried out usingvarying amounts of hydrogen. H₂ is the partial pressure of hydrogen aspsig, measured as the pressure drop from a 1 liter vessel. The resultsare summarized in Table 7.

                  TABLE 7                                                         ______________________________________                                        H.sub.2                                                                            Activity  MI      SR   Density HI    log MW                              ______________________________________                                        10   11507     0.04    44   0.9484  10.84 5.4786                              40   10313     0.87    32   0.9537  8.40  5.1105                              70    7136     7.15    33   0.9593  7.98  4.0250                              ______________________________________                                    

Table 7 demonstrates the effect of hydrogen on the resulting polymer.The results are similar to those using DEAC as cocatalyst. The meltindex, and density increase, and the HI, molecular weight, and activitydecrease.

EXAMPLE VIII

Another series of polymerization runs was carried out varying the gramsof hexene as comonomer charged to the reactor. The results aresummarized in Table 8.

                  TABLE 8                                                         ______________________________________                                        Hexene Activity  MI     SR   Density                                                                              HI    log MW                              ______________________________________                                         0     10026     0.28   36   0.9609 11.61 5.2945                              25     10313     0.87   32   0.9537 8.40  5.1105                              50      8768     1.33   32   0.9494 7.93  5.0492                              ______________________________________                                    

Table 8 demonstrates that hexene is incorporated into the polymer asindicated by the decreasing density and molecular weight and increasingmelt index.

EXAMPLE IX

In Example IX a series of polymerization runs was carried out varyingthe length of time used in the polymerization reaction. Time isexpressed in minutes in Table 9. The results are summarized in Table 9.

                  TABLE 9                                                         ______________________________________                                        Time Activity  MI      SR   Density HI    log MW                              ______________________________________                                        15.0 14336     1.47    33   0.9557  10.43 5.0531                              37.5 10313     0.87    32   0.9537  8.40  5.1105                              60.0  8664     0.56    32   0.9536  7.56  5.1367                              ______________________________________                                    

TEA is similar to DEAC in its response to time, producing polymers withincreasing molecular weight with increasing time.

EXAMPLE X

A series of polymerization reactions was run varying the temperature ofthe polymerization reaction. The results are summarized in Table 10. Thetotal pressure in these runs remains constant, so that as thetemperature increases, the amount of ethylene decreases.

                  TABLE 10                                                        ______________________________________                                        Temp   Activity  MI     SR   Density                                                                              HI    log MW                              ______________________________________                                        80° C.                                                                        17914     0.25   29   0.9491 6.95  5.2625                              90° C.                                                                        10313     0.87   32   0.9537 8.40  5.1105                              100° C.                                                                        2346     5.62   46   0.9602 15.23 4.9619                              ______________________________________                                    

Catalyst activity and molecular weight decrease with increasingtemperature, while the HI and density increase.

Examples I-X demonstrate that useful catalyst systems are produced byreacting a metal halide, an alcohol, and a transition metal compound inconjunction with an organoaluminum cocatalyst. In Examples I-V, goodcatalyst activity for producing polymer with bimodal molecular weightdistribution is exhibited by using DEAC as cocatalyst. In Examples VI-Xusing TEA as cocatalyst, polymer with broad molecular weightdistribution that approaches multimodal molecular weight distribution isproduced.

While this invention has been described in detail for the purpose ofillustration, it is not to be construed or limited thereby, but isintended to cover all changes and modifications within the spirit andscope thereof.

I claim:
 1. A polymerization catalyst system prepared by a processcomprising:(1) contacting neodymium trichloride with 1,2-octanediol toform a neodymium trichloride solution;(2) contacting the solution of (1)with titanium tetrachloride to form a catalyst; and (3) contacting saidcatalyst with diethylaluminum chloride to produce said catalyst system.2. A process for producing a catalyst system comprising:(1) contactingneodymium trichloride with 1,2-octanediol to form a neodymiumtrichloride solution; (2) contacting the solution of (1) with titaniumtetrachloride to form a solid catalyst; and (3) contacting said catalystwith diethylaluminum chloride to produce said catalyst system; whereinsaid 1,2-octanediol is present in an amount in the range of 3 to 15moles of alcohol per mole of neodymium trichloride; said titaniumtetrachloride is present in an amount in the range of 1 to 100 moles oftitanium tetrachloride per mole of neodymium trichloride; saiddiethylaluminum chloride is present in the range of 5 to 700 moles ofdiethylaluminum chloride per mole of titanium tetrachloride; whereinsaid contacting in step (1) is carried out at a temperature of from 20°to 75° C.; and a pressure of 0 to 50 psig; for a time within the rangeof from 5 to 10 hrs; and said contacting in step (2) is carried out at atemperature of from 0° to 100° C.; and a pressure of 0 to 50 psig; for atime within the range of from 5 min to 10 hrs.
 3. A catalyst systemproduced according to the process of claim 2.